Joint seal

ABSTRACT

An elongated joint seal for sealing a gap between two surfaces comprising a trunk and at least two resilient members extending one to each side of the trunk. The fingers in use contacting the surfaces of the gap, the trunk being substantially rigid to enable insertion of the seal into the gap.

The present invention relates to a joint seal for sealing a gap between two surfaces and a method for sealing a gap between two surfaces using a joint seal.

BACKGROUND OF THE INVENTION

There are many techniques and products available for sealing gaps between structures such as concrete tilt slabs or slab flooring. One method is the traditional technique of corking joints which generally includes inserting a foam backing rod into a gap or expansion gap, and retaining and sealing the backing rod in the gap by using a corking compound injected into the gap using an injection gun. The corking compound used is typically a polymer that sets in position and is applied across the gap to adhere to the opposing wall surfaces of the gap.

The drawbacks with this technique is that the corking compound/foam backing rod combination allow limited joint movement and over the years the polymer corking compound hardens and shrinks which leads to cracking and failure. A joint seal of this kind generally requires replacement after 10 years.

Furthermore, this process is expensive when applied to large gaps because a greater volume of corking compound and foam backing rod is required. Difficulty is also encountered in using this method on large vertical gaps because the corking compound can not be applied in one application due to sagging under gravity of the un-set corking compound. This technique can also be untidy, toxic, flammable and cleaning after use generally requires solvents that are known to be carcinogenic. This technique also makes it difficult to detect faults and flaws in installation and to determine whether the correct volume and depth of corking compound has been achieved.

Another known technique uses a joint compression or expansion joint seal generally made of an extruded length of rubber containing hollow channels defined by internal webs. Gap installation of this type of seal requires a large force in order to squeeze the seal into the gap. This often results in a difficult and lengthy installation process that is exacerbated if the gap walls are not smooth, parallel and generally uniform along the wall lengths.

The drawbacks with all these known techniques is that they are difficult, and in some cases almost impossible, to install in a plane that is other than horizontal. Many sealing systems are cumbersome to install vertically or overhead and/or may require an installation force that can not be achieved in a vertical plane or directed upwardly. Typically a correctly sized seal must be chosen to suitably fill the entire length of a particular sized gap. Many seals have limited working movement hence limited gap size variations. In transporting and handling, known seals are heavy, bulky, awkward and expensive to freight.

A seal is therefore required to seal a gap oriented in any plane and which is simple to install and effective in its use as a seal.

SUMMARY OF THE INVENTION

According to the present invention there is provide an elongated joint seal for sealing a gap between two surfaces, comprising a trunk and at least two resilient members extending one to each side of the trunk, the fingers in use contacting the surfaces of the gap, the trunk being substantially rigid to enable insertion of the seal into the gap.

In a preferred embodiment the trunk is defined by a seal body at least partly encapsulating a substantially rigid spine, the resilient members being formed with the seal body. The spine is located between folded trunk walls of the seal body. The seal body is preferably an extruded strip of resilient material, and typically an elastomeric material. The spine is typically formed from plastics or metal.

The joint seal is preferably formed by longitudinally folding in half the seal body, which before folding is a strip of resilient material containing the resilient members defined by fins, or fingers, on one side. The spine is located between the folded walls of the folded seal body, namely within the fold.

In cross-section the joint seal is preferably arrow shaped having a nose and a tail and preferably, the members are defined by three fins on each opposite side of the trunk.

According to another aspect of the present invention there is provided a joint seal for sealing a gap between two surfaces, comprising:

-   -   an elongated strip of resilient material having members         extending laterally to one side of the strip; and     -   a substantially rigid spine for driving the elongated strip into         a gap whereby the spine folds the strip along the length of the         strip into the gap to form a substantially rigid trunk         encapsulating the rigid spine and with at least one member         located on each opposite side of the trunk contacting the         surfaces of the gap.

The strip preferably has an indented nose for receiving a leading end of the spine. The strip is preferably extruded and has, for example, six fins, wherein three fins position on either side of the indented nose.

The spine is preferably a thin straight extruded piece. The spine may have angled barbs to assist in anchoring the spine between the trunk walls of the strip. For stability the spine may have a trailing end, or head, that is shaped as a “Y” wherein the Y-shaped head sits recessed in the gap. Alternatively the head may be “T” shaped to sit across an entrance of the gap resting on the surfaces to sit flush across the gap. The trunk walls may be provided with nodes corresponding to the barbs on the spine.

In accordance with another embodiment of the present invention there is provided a method of sealing a joint gap between two surfaces comprising:

-   -   aligning along the gap an elongated sealing strip of resilient         material having sealing members extending laterally to one side         of the strip;     -   driving the strip into the gap by forcing a substantially rigid         spine along a longitudinal line of the strip such that the strip         folds as it is driven into the gap and the members contact the         surfaces on either side of the gap.

In a preferred embodiment the strip is longitudinally folded in half along a centre line although it is understood that the longitudinal fold of the strip may be uneven.

A mallet or hammer is preferably used to drive the spine and strip into the gap. The method may include the use of adhesives between the sealing strip and the gap surfaces or the use of a lubricant between the sealing strip and gap surfaces.

The sealing strip may be provided in a continuous length and rolled for handling whereby the strip is cut to the desired length for use. The spine does not need to extend along the entire length of the sealing strip but may be provided in shorter lengths, such as 1 m to 1.5 m.

The spine material may include an intumescent as a fire retardant.

The body and spine of the joint seal may be co-extruded as a single elongated component or cross head extruded where the rigid spine is encapsulated within the body to form a single elongated component.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments, incorporating all aspects of the invention, will now be described by way of example only with reference to the accompanying drawings in which:

FIG. 1( a) illustrates a joint seal in accordance with a first embodiment of the invention;

FIG. 1( b) illustrates the joint seal of FIG. 1( a) inserted in a gap;

FIG. 1( c) is an isometric view of FIG. 1( a);

FIG. 1( d) is an isometric view of FIG. 1( b);

FIG. 2( a) illustrates a second embodiment of a joint seal;

FIG. 2( b) illustrates the joint seal of FIG. 2( a) inserted in a gap;

FIG. 2( c) is an isometric view of FIG. 2( a);

FIG. 2( d) is an isometric view of FIG. 2( b);

FIG. 3( a) illustrates a third embodiment of a joint seal;

FIG. 3( b) illustrates the seal of FIG. 3( a) inserted in the gap;

FIG. 3( c) is an isometric view of FIG. 3( a); and

FIG. 3( d) is an isometric view of FIG. 3( b).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The drawings show embodiments of a joint seal 10 for inserting into a gap 12 located between two surfaces 14 such that the joint seal 10 acts in compression or expansion between the two surfaces 14. The surfaces may be of any known material used for flooring, walls, partitions, ceilings, fascias, and the like including concrete, wood, metal, glass, polymers, composites, etc.

In its installed form as illustrated in FIGS. 1( b), 2(b) and 3(b) the joint seal 10 is elongated and includes a substantially rigid trunk 22 and at least one member extending on either side of the trunk 22 wherein the members are long fins or fingers 24 that are resilient with respect to the trunk 22 such that the fingers 24 bend to contact the side walls 16 of gap 12. Fingers 24 are adapted to lie in a compressed state against side walls 16 and resiliently move with any variations in the gap 12, namely any widening or narrowing, to maintain sealing of the gap.

The trunk of the joint seal 10 is substantially rigid for facilitating insertion of the joint seal 10 into the gap 12. The rigidity of the trunk is brought about by a substantially rigid core or spine 30 which is encased in resilient trunk walls 26 from which fingers 24 extend.

Resilient trunk walls 26 and fingers 24 form part of a seal body 20 which is an extrusion of resilient sealing material that, in the embodiments shown, is a separate piece to the rigid spine 30. Spine 30 locates wholly or partly in the fold between the trunk walls 26 of the seal body 20.

It is however understood that the spine 30 may be formed by extrusion in one piece together with seal body 20, or otherwise attached to the seal body, wherein the trunk is made substantially rigid.

Seal body 20 which includes trunk walls 26 and three fingers on each trunk wall 26, is an extrusion of a resilient material, such as an elastomeric material. Examples of suitable materials include ethylene-propylene-diene (EPDM) thermoset elastomers or silicone thermoset elastomers which advantageously exhibit long term aging, have ozone and weathering properties and good colour retention. These materials also have good compression set properties which are advantageous for the purpose of the joint seals. Using a silicone elastomer further allows the colour of the joint seal to be matched to any desired colour and in particular the façade 15 colour of the surfaces 14 to give the appearance of a single continuous façade surface.

Depending on the application of the joint seal the material properties of the seal body 20 may include other characteristics. For example, silicone and Neoprene rubber may be compounded to meet fire protection ratings with the possible inclusion of an intumescent material to contain fire and smoke. The intumescent material, commonly in the form of flakes of graphite, has the effect of retarding the spreading of fire by activating to foam and char under heat. The intumescent material may be added into the material compound of the extruded seal body 20 or spine 30 or may be laid in strips, or otherwise, alongside or on the extruded body or spine.

Thermoplastics may also be used to form seal body 20, such as a flexible polyvinyl chloride (PVC). While a flexible seal body 20 is preferable, a more rigid material may be used, for example, in gaps where large gap movement is not expected but seal integrity against harsh conditions is important.

Because PVC in general exhibits poor compression and average long term weathering, these characteristics can be compensated by adhering the PVC to the side walls of the gap using for example a flexible adhesive and/or coating the PVC with a weather resistant polymer coating or rigid cover to increase the weathering properties of the seal.

Where the joint seal 10 is expected to be fitted into a gap size at the upper limits of the recommended gap size or where a greater level of retention and or sealing of the joint seal is desirable adhesive may be applied between the joint seal 10 and gap walls 16. In particular this is useful if the material of the seal body 20 has poorer compression set values compared to a seal body made from a correctly compounded thermoset elastomer. Where the joint seal 10 is expected to be fitted into a gap size at the lower limits of the recommended gap size a lubricant may be applied on the joint seal and/or side walls 16 of the gap to facilitate insertion of the joint seal into the gap.

Other applications that may be required of the joint seal include oil or gas retention which would require the joint seal material to be selected and compounded to meet the special requirements of such applications.

As illustrated in FIGS. 1( a), 2(a) and 3(a), in the preferred embodiment the seal body 20 is extruded as a substantially flat piece or ribbon comprising trunk walls 26, fingers 24 extending from one side of the flat seal body 20 and a leading nose 23 joining trunk walls 26 and having an indentation that is adapted to receive a leading edge of spine 30.

The embodiments illustrate three fingers 24 to each side of trunk 22. More or less fingers may be provided depending on the application and depth of the gap. A joint seal having between one and five fingers to each side of the trunk is reasonably envisaged.

In its unfolded and flattened state the leading nose 23 of seal body 20 rests slightly forward of trunk walls 26 and in the embodiment shown in FIG. 2( a) the trunk walls flare behind nose 23 by an approximate angle α of 10°.

In use, seal body 20 is driven into the gap by the rigid spine 30 and in doing so folds from the flat configuration illustrated in FIGS. 1( a), 2(a) and 3(a) to the folded configuration as illustrated in FIGS. 1( b), 2(b) and 3(b) where the seal resembles an arrow shape having a head, defined by nose 23, and a tail. The resilient fingers 24 fold back during insertion to bear against the gap walls when inserted.

The spine is a longitudinal and thin strip 33 made from a rigid material such as coated steel, stainless steel, aluminium, composite material or a polymer such as rigid PVC. The spine may be cut from sheets or may be extruded.

It is an advantage that the spine be protected against ultraviolet light and includes other characteristics depending on its application such as including an intumescent for fire protection (whether by including the intumescent in the compound material or attaching strips to the spine).

In the inserted configuration seal body 20 encapsulates the spine 30 between the trunk walls 26 to create a joint seal with a substantially rigid trunk and resilient side fingers 24. A leading end 31 of spine 30 is designed, before insertion, to be aligned along the indented groove forming nose 23 of seal body 20. Seal body 20 is aligned longitudinally along the gap 12 into which the joint seal 10 is to be inserted. A force is then applied to an outer end 32 of spine 30 to drive the spine, and thereby the seal body from its nose, into the gap. The driving force may be applied by a hammer, mallet, etc and because the force is applied to a central leading point of the seal body the remaining parts of the seal body easily follow and insert into the gap.

The spine 30 may be constructed to not only provide rigidity to the trunk 22 of joint seal 10 but to also provide protection to the seal body and to ensure stability of insertion. Spine 30 in its simplest form as illustrated in FIG. 2( a) is a thin rigid strip 33. As illustrated in FIGS. 1( a) and 3(a), strip 33 may be provided with angled barbs 35 for anchoring spine 30 in between trunk walls 26 of the seal body 20 when inserted. Barbs 35 not only catch on the surface of trunk walls 26 but may inter-engage with nodes 27 provided on the internal surface of trunk walls 26 to more securely anchor spine 30 in between trunk walls 26.

Outer end 32 of spine 30 may be provided with features to, as discussed, enhance the stability and protection of the joint seal 10. FIG. 1( a) illustrates a forked outer end 32 of spine 30 in the shape of a “Y”. This shape as illustrated in FIG. 1( b), allows the top edges of the Y shape to bear against the side walls 16 of gap 12 under compression to thereby hold joint seal 10 in position.

FIG. 3( a) illustrates another version of spine 30 which includes a substantially flat or slightly convex outer end in the shape of a “T” wherein the head of the T is adapted to lie across the opening of gap 12 and across the façade 15 of the surfaces 14. This is useful where a flush appearance is required of the joint seal, for example to prevent ingress of particles and moisture into the seal. Where the seal is inserted in a gap between flooring the T-shaped spine provides a pedestrian walk over such that heels, wheels, etc, do not become caught in the gap.

The seal body 20 is provided in a continuous length and is typically rolled up on a spool and cut to the desired length on site. Because the seal body before application is substantially flat a large amount of seal body may be rolled onto a spool for easy handling and transportation. Additionally, a spool of rolled seal body material is relatively light compared to the same length of some known joint seals, particularly bulky joint seals constructed to have channels.

In use, the spine need not extend along the entire length of the seal body but may be inserted at spaced intermissions as required. Accordingly, the spine may be provided in lengths of 1 to 1.5 m or any other suitable lengths for convenience handling.

The spine may not necessarily be a plain flat strip, it may be notched or formed to allow for the 1.0 m to 1.5 m lengths to be easily aligned and joined during installation. It may be notched or otherwise formed to allow for coiling in packaging and transport, to allow for flexing in desired installation radii or to remove potential stresses.

From the above it is understood that joint seal 10 may be provided ready for use in at least two embodiments. In the first embodiment the seal body 20 and spine 30 are provided as separate components whereby spine 30 drives the nose of the substantially flat seal body into a gap in order to fold seal body 20 around spine 30 when fully inserted in the gap.

In another embodiment joint seal 10 is provided for use with seal body 20 already encapsulating the substantially rigid spine 30 such that the joint seal resembles an arrow head. In this embodiment the joint seal is similarly driven into a gap by applying a driving force on the outer end of the spine 30.

Following on from the latter embodiment described above the seal body 20 and spine 30 may be formed as a single component by a single extrusion process which may incorporate different materials or a greater concentration of the same materials at the trunk of the joint seal in order to create a substantially rigid trunk. In another version the seal body and spine may be cross head extruded where the rigid spine is encapsulated within the body to form a single elongated component. Alternatively, seal body 20 and spine 30 may be formed by separate manufacturing processes and assembled by adhesion or other suitable means in a further process.

In yet another embodiment the resilient fingers 24 may be provided by adhesive or interlocking attachment or otherwise joined directly onto the sides of the spine 30. A seal body would not be required in this instance and the sealing joint would largely comprise a rigid spine with resilient fingers extending from each side of the spine.

The present joint seal is very simple to install in any orientation, not just a horizontal surface, because the seal requires only that the seal body be aligned with the gap and the spine forced onto the seal body to drive both the seal body and spine into the gap. This may be carried out on a vertical surface where traditional techniques struggle with seal insertion. Additionally, the joint seal and its insertion can be easily applied overhead or at a height, for example in building fascias where it has been difficult, if not impossible, to install seals using traditional joint seals and techniques.

In addition to the joint seal being particularly useful in its application in vertical gaps the joint seal is useful for floor expansion joints in, for example, concrete floors in multiple storey buildings. In order to fire rate a building between storeys, expansion joints are packed with fire retardant mats, seals and fixed over with metal cover plates. Aside from being costly, metal cover plates under floor coverings are undesirable.

The present joint seal alleviates these problems by providing an easy to install and fire rated floor joint. The embodiment illustrated in FIGS. 3( a) to 3(d) is useful with this application but it may also be desirable to use one or the other embodiments discussed above. In these cases the gap above spine 30 may be filled with a fire rated liquid sealant which is poured in the gap over joint seal 10 to a level that is flush with floor surface. The spine 30 and/or seal body 20 would preferably include intumescent.

The joint seal may come in a variety of sizes depending on the size of the gap to be sealed, but generally a one size seal may be used for a variety of gap variations because fingers 24 are able to flex to withstand expansion and compression experienced with movement of gaps.

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention. 

1. An elongated joint seal for sealing a gap between two surfaces, comprising a trunk and at least two resilient members extending one to each side of the trunk, the fingers in use contacting the surfaces of the gap, the trunk being substantially rigid to enable insertion of the seal into the gap.
 2. The joint seal claimed in claim 1 wherein the trunk is defined by a seal body at least partly encapsulating a substantially rigid spine, the resilient members being formed with the seal body.
 3. The joint seal claimed in claim 2 wherein the seal body is an extruded strip of resilient material that is longitudinally folded upon itself with the spine located within the fold.
 4. The sealing joint claimed in claim 3, wherein the resilient members are resilient fingers of which there are one to five fingers to each side of the trunk.
 5. A joint seal for sealing a gap between two surfaces, comprising: an elongated strip of resilient material having sealing members extending laterally to one side of the strip; and a substantially rigid spine for driving the elongated strip into a gap whereby the spine folds the strip along the width of the strip into the gap to form a substantially rigid trunk encapsulating the rigid spine whereby at least one sealing member locates on opposite sides of the trunk so as to contact the surfaces of the gap.
 6. The joint seal claimed in claim 5, wherein the strip contains an indented nose for receiving a leading end of the spine.
 7. The joint seal claimed in claim 5, wherein the strip is made of an extruded elastomeric material, and the spine is extruded or formed from a sheet in plastics, metal or a composite.
 8. The joint seal claimed in claim 5, wherein the spine has angled barbs for anchoring the spine within folded walls of the strip,
 9. The joint seal claimed in claim 5, wherein the spine has a trailing end that is “Y” or “T” shaped.
 10. The sealing joint claimed in claim 5 wherein the joint includes an intumesent material.
 11. The sealing joint claimed in claim 5 wherein the strip and the spine are co-extruded or cross head extruded as a single elongated component.
 12. A method of sealing a joint gap between two surfaces comprising: aligning along the gap an elongated sealing strip of resilient material having sealing members extending to one side of the strip; driving the strip into the gap by forcing a substantially rigid spine along a longitudinal line of the strip such that the strip folds as it is driven into the gap and the members contact the surfaces on either side of the gap.
 13. The method claimed in claim 12, including pre-folding the sealing strip along the longitudinal line to encapsulate the rigid spine and then driving the sealing strip and spine into the gap such that the sealing members contact the surfaces on either side of the gap.
 14. The method claimed in claim 12, including driving the spine along a centre line of the strip to longitudinally fold the strip in half into the gap.
 15. The method claimed in claim 12, including driving the strip into the gap by hammering a head of the spine onto the strip.
 16. The method claimed in claim 12, including applying an adhesive or a lubricant along the side of the strip having the sealing members.
 17. The joint seal claimed in claim 3, wherein the strip is made of an extruded elastomeric material, and the spine is extruded or formed from a sheet in plastics, metal or a composite.
 18. The joint seal claimed in claim 3, wherein the spine has angled barbs for anchoring the spine within folded walls of the strip.
 19. The joint seal claimed in claim 3, wherein the spine has a trailing end that is “Y” or “T” shaped.
 20. The sealing joint claimed in claim 1 wherein the joint includes an intumesent material. 